Loose leaf binder



May 9, 1939- P o. UNGER LOOSE LEAF BINDER FiledApril 22, 1937 2 Sheets-Sheet l Huw.

Elue-ato? z HIHUHIIHW paul O. TQ@ 7 @39' May 9, 1939. P. o. UNGER LOOSE LEAF BINDER Filed April 22, 1937 2 Sheets-Sheet 2 Y ffl Ille I Patented May 9, 1939 LOOSE LEAF BINDER.

Paul O. Unger, Elmhurst, Ill., assigner to Wilson- Jones Company, Chicago, Ill., a corporation of Massachusetts Application April 22, 1937, SerialNo. 138,288

2 Claims.

This invention relates to loose leaf binders of the type adapted to retain the sheet contents by pressure, and particularly to means for increasing the security of the sheet retaining structure.

It is an object of this invention to provide simple and efficient means for facilitating the retention of sheets in a loose leaf binder having no sheet retaining posts. Other objects kof this invention will become apparent upon reading the following description, taken in conjunction with the accompanying drawings, in which Figure 1 is a cross sectional View through a loose leaf binder embodying the invention;

Figure 2 is a cross sectional View taken along the line II--II of Figure 1;

Figure 3 is a Cross sectional view taken along the line III-III of Figure 1;

Figure 4 is a cross sectional view taken along the line IV-IV of Figure l;

Figure 5 is a detail View of one embodiment of the spreader sheet; and

Figure 6 is a detail view of another embodiment of the spreader sheet.

The loose leaf binder to which this invention is applied consists of a pair of clamping plates 2 and 3 which are movable transversely relative to each other. Cover members l are hinged to the clamping plates, as indicated at 5. The clamping plates 2 and 3 are provided with ilanges or back members 2' and 3. The ends of the back member 2 are bent over, as indicated at 5, to form guide channels in which the ends of the back member 3' are moved. Separation of the back members may be prevented by any suitable means such as interengaging tongues on the bent over portion 6 and the back member 3.

The clamping plates 2 and 3 are connected by a pair of posts l each of which consists of a tubular section 8 rigidly secured to the clamping plate 2, as indicated at S, and a second tubular section Ill secured to the clamping plate 3, as indicated at I i, and adapted to telescope into the section- 8. A coiled spring l2 is contained in each telescopic post l and normally tends to expand to separate the clamping plates 2 and 3.

The clamping plates 2 and 3 are also connected by a pair of telescopic locking posts I3. Each locking post I3 consists of a solid section I4, rigidly secured to the clamping plate 2, as indicated at I5, and a tubular section I6 adapted to telescope over the solid section I5 and rigidly secured to the clamping plate 3, as indicated at il. The solid section I@ is provided with an enlarged head i3 and the tubular section I6 is provided with a turned in shoulder I9 to prevent separation ofthe sections I4 and I6. The head I8 is provided with a plurality of inclined recesses 2li each of which is provided with a locking ball 2l. The inner surface of the tubular section I6 is provided with a plurality of circularly or helically disposed grooves 22. When the binder is in the position shown in Figure 4, a slight pressure on the clamping plate 3 will release the balls 2l so that gravity will cause them to fall into the recesses 20 out of engagement with the grooves 22. The springs I 2 will then expand the binder to open position. If the binder is reversed from the position shown in Figure 4, the lbinder may be compressed. When the compressive force is released the springs l2 tend to expand the binder, but the force of gravity causes the balls 2| to move to the lowermost position possible, and the balls 2l engage the grooves 22 to hold the binder in compressed position.

An inspection of Figure 1 shows the arrangement of the posts 'l and I3. A stack of sheets 23 is positioned in the binder with one edge between the two sets of posts. This arrangement permits the use of imperforate sheets in the binder. Although the desire to use imperforate sheets in binders of this type has been long felt, because of the ease with which such sheets may be inserted into posting or bookkeeping machines, it has been impossible heretofore to use a binder of this type with imperforate sheets because the sheets would spill out of the binder. It has been necessary to provide posts passing through the sheets to prevent their spilling from the binder.

The back members 2' and 3 are each provided ,y

with a plurality of interengaging plates 2d which have roughened surfaces in Contact with the sheets 23 to prevent the sheets from slipping when the binder is open in position for posting.

My improved binder has a channel member 25 riveted or welded to each of the back members 2 and 3. The channel member 25 is preferably l formed of metal, but may be of any suitable material. Each channel member contains a strip of material 25 forming a projection extending above the edges o-f the channel member. This strip 26 is preferably formed of rubber, but any resilient material is satisfactory. The strip must have a comparatively high coefficient of friction or must be covered with material having that characteristic to prevent the sheets from slipping past the strip 26. It is preferable to have the strip 26 triangular in cross section, as shown in Figure 3, but any shape in which the area of contact with the sheets is comparatively small is permissible. The strip 26 may be replaced CII Without taking the binder out of service if it becomes damaged or loses its resilience.

A separator sheet or spreader member 2l' is positioned near the center of the stack of, sheets to be contained in the binder. The separator sheet is provided With an enlarged end at its binding edge. This enlarged end is preferably formed by Wrapping a strip of Wood 29 o-r similar rigid material with a strip 30 of rubber, emery cloth or other fabric and adhering the Wrapping material to the wood and to the sheet 21 as shown in Figure 5. The strip 3E! should be of material having a high coefficient of friction on its exposed surface so that it will not slip relative to the sheets 23.

A different form of spreader is shown in Figure 6 in which a strip 3| of rubber or similar material is provided With a slit 32 into which the sheet 33 is secured. The separator sheets are preferably provided with a tab 34 to facilitate handling of the sheet. The spreader or separator sheet may be omitted in cases Where the thickness of the sheet contents of the binder is less than three and one half inches, but I prefer to employ a spreader or separator sheet regardless of the amount of paper.

As seen in Figure 3, the strips 26 are positioned adjacent the edge 0f the clamping plate as far as possible from the binding edge of the sheets 23. When the clamping plates 2 and 3 are compressed, the sheets 23 are compressed along the line of contact with the strip 26 and are fanned outwardly betweenthe strip 2B and the back members 2' and 3', as indicated at 35. The resiliency of the strip 26 enables it to adjust itself to any inequalities in the pressure so as to hold the sheets firmly along the entire line of contact with the strip 26. The enlarged end 28 of the spreader member is positioned as close as possible to the binding edge of the sheets 23. This enlarged portion 28 of the spreader member spreads the binding edges of the sheets 23 to fan them towards the clamping members 2 and 3, as indicated at 36. 'Ihe spreader member acts like the keystone in an arch and cooperates with the strips 26 to retain the sheets 23 in the binder.

Although I have described a preferred embodiment of my invention in detail, it Will be understood that the description is illustrative, rather than restrictive, as many details may be varied or changed without departing from the spirit or scope of the invention. Accordingly, I do not desire to be restricted to the exact structure described, except as limited by the appended claims.

I claim:

l. A spreader sheet for use in a compression binder comprising a sheet of paper, a rigid strip, and a strip of, frictional material secured to said rigid strip and. said sheet of paper.

2. In a loose leaf binder, a pair of clamping plates, a channel member rigidly secured to the inner surface of each of said clamping plates,

and a resilient member of approximately trlangular cross section secured in each of said channel members and projecting above the edges of said channel members.

PAUL O. UNGER. 

